block: BFQ: Refactor bfq_exit_icq() to silence sparse warning

Currently building for C=1 generates the following warning:
block/bfq-iosched.c:5498:9: warning: context imbalance in 'bfq_exit_icq' - different lock contexts for basic block

Refactor bfq_exit_icq() into a core part which loops for the actuators,
and only lock calling this routine when necessary.

Signed-off-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20240614090345.655716-4-john.g.garry@oracle.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
John Garry 2024-06-14 09:03:45 +00:00 committed by Jens Axboe
parent c3042a5403
commit 66088084fd

View File

@ -5463,29 +5463,10 @@ static void bfq_exit_icq_bfqq(struct bfq_io_cq *bic, bool is_sync,
}
}
static void bfq_exit_icq(struct io_cq *icq)
static void _bfq_exit_icq(struct bfq_io_cq *bic, unsigned int num_actuators)
{
struct bfq_io_cq *bic = icq_to_bic(icq);
struct bfq_data *bfqd = bic_to_bfqd(bic);
unsigned long flags;
unsigned int act_idx;
/*
* If bfqd and thus bfqd->num_actuators is not available any
* longer, then cycle over all possible per-actuator bfqqs in
* next loop. We rely on bic being zeroed on creation, and
* therefore on its unused per-actuator fields being NULL.
*/
unsigned int num_actuators = BFQ_MAX_ACTUATORS;
struct bfq_iocq_bfqq_data *bfqq_data = bic->bfqq_data;
/*
* bfqd is NULL if scheduler already exited, and in that case
* this is the last time these queues are accessed.
*/
if (bfqd) {
spin_lock_irqsave(&bfqd->lock, flags);
num_actuators = bfqd->num_actuators;
}
unsigned int act_idx;
for (act_idx = 0; act_idx < num_actuators; act_idx++) {
if (bfqq_data[act_idx].stable_merge_bfqq)
@ -5494,9 +5475,30 @@ static void bfq_exit_icq(struct io_cq *icq)
bfq_exit_icq_bfqq(bic, true, act_idx);
bfq_exit_icq_bfqq(bic, false, act_idx);
}
}
if (bfqd)
static void bfq_exit_icq(struct io_cq *icq)
{
struct bfq_io_cq *bic = icq_to_bic(icq);
struct bfq_data *bfqd = bic_to_bfqd(bic);
unsigned long flags;
/*
* If bfqd and thus bfqd->num_actuators is not available any
* longer, then cycle over all possible per-actuator bfqqs in
* next loop. We rely on bic being zeroed on creation, and
* therefore on its unused per-actuator fields being NULL.
*
* bfqd is NULL if scheduler already exited, and in that case
* this is the last time these queues are accessed.
*/
if (bfqd) {
spin_lock_irqsave(&bfqd->lock, flags);
_bfq_exit_icq(bic, bfqd->num_actuators);
spin_unlock_irqrestore(&bfqd->lock, flags);
} else {
_bfq_exit_icq(bic, BFQ_MAX_ACTUATORS);
}
}
/*